1. Field of Invention
This invention relates to a wire harness structure for connecting separate (divided) wire harnesses together, and more particularly to a wire harness structure capable of efficiently splicing (Going) wires of the wire harnesses together.
2. Description of Related Art
Electrical equipment mounted on an automobile obtain electric power and a lot of information fed from switch sensors and the like, through wires, and therefore wire harnesses, having a large amount of wires concealed from the view, are installed in the vehicle, Here, the term xe2x80x9cwire harnessxe2x80x9d means a bundle of wires of various kinds joined together by a corrugated tube, a tape or the like.
In view of the productivity and the ability of mounting on a vehicle body, the wire harnesses of suitable lengths are provided in a divided manner, and are mounted respectively at various portions, such as an engine room, an instrument panel a door and a seat, and the wire harnesses are connected together through suitable connection means such as a connector. This is usually referred to as xe2x80x9cwire-to-wire connectionxe2x80x9d.
The wire harnesses connecting the electrical equipments are arranged in complicated paths, and therefore, parts of wires forming the wire harnesses need to be spliced, and particularly at the wire-to-wire portion, the wires often need to be spliced over the wire harnesses This has been the cause of an increased number of the wires.
One example of methods of thus splicing wires over a plurality of wire harnesses is shown in FIG. 11.
In FIG. 11, a wire harness 1 is mounted in an engine room, and a wire harness 2 is mounted on an instrument panel. These wire harnesses 1 and 2 are connected together through a connector 3.
A circuit group 4 of the wire harness 1 comprises two wires A and one wire B. and in FIG. 11, the two lower wires B and A are spliced to the uppermost wire A.
As shown in FIG. 13 described in detail later, the wires A, B and C are used in accordance with equipment specifications. More specifically, the wires A are connected to units provided as standard (that is, in all variations), and wires B and C are connected to units provided in accordance with the variations.
As shown in FIG. 11, a circuit group 5 of the wire harness 2 comprises wires A, B and C, and the two lower wires A and C are spliced to the uppermost wire B.
Therefore, these wires A to C are spliced over the wire harnesses 1 and 2 through the connector 3.
As shown in FIGS. 12A and 12B, with respect to the splicing of the wires A to C of the circuit groups 4 and 5, a sheath is removed from an arbitrary portion of a sheathed wire 6, and a wire 7 is connected to this sheath-removed portion, and these connected portions are spliced together by press-deforming a press-fastening member 8.
Assuming that with respect to wire harnesses of this kind, there are four Item Nos. 1 to 4 of splice specifications as shown in FIG. 13, it is necessary to splice the circuit groups 4 and 5 of the wire harnesses 1 and 2 in accordance with the splice specifications (including four Item Nos. 1 to 4) after removing the sheaths from the wires A to C. Therefore, it has been necessary to produce four kinds of circuit groups corresponding respectively to the four Item Nos. 1 to 4, and therefore the production cost of the wire harnesses has increased, and the production has been very cumbersome.
In order to overcome such a disadvantage, methods of splicing wires by the use of a joint connector have been extensively used. One example of such splicing methods is shown in FIG. 14. In FIG. 14, the construction of wire harnesses is similar to that shown in FIG. 11, and therefore, only splice portions will be described.
In FIG. 14, two wires A and one wire B are spliced to a circuit group 10 of a wire harness 1 through a joint connector 100, and one wire A, one wire B and one wire B are spliced to a circuit group 11 of a wire harness 2 through another joint connector 101.
As shown in FIG. 15, each of the joint connectors 100 and 101 comprises a connector 102, into which crimp-type terminals secured respectively to one ends of the wires A to C are inserted, and a bus bar connector 9 containing bus bars 9a. 
As shown in FIG. 14, the wires 10 and 11, connected through a connector 3, are connected to the joint connectors 100 and 101, respectively, and the wires A to C are spliced over the wire harnesses 1 and 2 through the wires 10 and 11.
In the splicing method using these joint connectors 100 and 101, merely by connecting the wires A to C to the joint connectors 6 and 7 in accordance with a selected one of the Item Nos. 1 to 4 (as shown in FIG. 13), the wires A to C can be spliced over the wire harnesses 1 and 2 in accordance with the selected Item Number. Therefore, it is not necessary to produce four kinds of wire harnesses corresponding respectively to the four Item Nos. 1 to 4, and there are achieved advantages that the cost of production of the wire harnesses is prevented from increasing, and that the production of the wire harnesses can be carried out easily.
In recent years, the control of automobiles has become more and more advanced, and many ECUs (electronic Control Units) have been mounted on the automobile, and the high-speed transfer of information between the ECUs for an engine, an ABS (Antilock Brake System), a transmission and the like has become indispensable. The transfer of signals between the engine, the ABS, the transmission and the like is enabled by a CAN (Control Area Network) forming a high-speed communication network in the automobile.
This CAN is capable of effecting a multiplex communication (that is, a serial data communication) at high speed, and therefore, the number of wires can be much reduced, and a compact, lightweight design of a wire harness can be achieved.
However, generally, a shielded wire, as shown in FIG. 18A, is used as a communication wire (that is, a serial data wire), used in the CAN, in order to eliminate the effects of noises, and such serial data wires are often spliced over wire harnesses.
One conventional method of splicing serial data wires of this type is shown in FIGS. 16 and 17. Basically, this method also uses joint connectors as in FIG. 14.
In FIGS. 16 and 17, reference numerals 11, 12 and 13 denote wire harnesses, and in view of the productivity and the ability of mounting on a vehicle body, these wire harnesses 11, 12 and 13 of suitable lengths are provided in a divided manner, and are mounted respectively at various portions such as an engine room, a dash panel and an instrument panel.
The wire harnesses 11 to 13 include their respective serial data wires 11a, 12a, 12b, 12c and 13a each including a shielded wire. As shown in FIG. 17B, each of these serial data wires comprises two wires a and b and one drain wire c. This drain wire c forms a metal film, and these wires are collectively covered with a tube.
As shown in FIG. 17A, one end of the serial data wire 11a is connected to an ECU 16, and the other end of this serial data wire 11a is connected to one end of the serial data wire 12a through a connector 14. The other end of this serial data wire 12a is connected to a joint connector 19 containing bus bars.
One end of the serial data wire 12b is connected to an ECU 17, and the other end of this serial data wire 12b is connected to the joint connector 19.
One end of the serial data wire 12c is connected to one end of the serial data wire 13a through a connector 15, and the other end of this serial data wire 12c is connected to the joint connector 19. The other end of the serial data wire 13a is connected to an ECU 18.
The serial data wires 12a to 12c are thus spliced to the joint connector, and with this arrangement the serial data wires 11a, 12a to 12c and 13a are spliced over the wire harnesses 11 to 13 as shown in FIG. 16.
In the connectors 14 and 15, the associated serial data wires, as well as associated wires for supplying power or merely for transmitting signals, are connected together (in a wire-to-wire manner).
The serial data wires 11a, 12a to 12c and 13a are different in length. For example, the serial data wire 11a is 1000 mm in length, and the serial data wire 12a is 700 mm in length. The serial data wires 12b and 12c are 500 mm in length, and the serial data wire 13a is 300 mm in length.
Other forms of serial data wire include a twist pair wire 41, shown in FIG. 18B, and a tubed wire 42 shown in FIG. 18C, and any other suitable form of wire can be used.
In this method of splicing the serial data wires, however, the single serial data wire usually comprises a plurality of wires. and therefore for splicing the serial data wires over the wire harnesses 11 to 13, sheaths are removed from the ends of the serial data wires 11a, 12a, 12c and 13a. Then the terminals are connected to these ends and inserted into the connectors 14 and 15. Therefore, there has been encountered a problem that the time and labor required for the sheath-removing step, the terminal-connecting step and the step of inserting the terminals into the connectors, increase as compared with the case of using simple wires, and the operation for splicing the serial data wires is cumbersome.
More specifically, as shown in an enlarged portion A of FIG. 18A, for connecting the terminals to the shielded wire, the tube is removed, the sheaths are removed from the ends of the two wires a and b, and the drain wire c in the form of a metal film is separated from the end portions of these wires, and is bundled. Thereafter, the terminals are press-fastened to the wires a and b, respectively. With respect to the drain wire c, a sheath is removed from an arbitrary portion of a wire, to which a terminal is beforehand press-fastened. The drain wire c is connected to this sheath-removed portion, and is press-fastened thereto by a press-fastening member. Thus, these operations are required. Incidentally, although terminal-connected portions of shielded wires, shown in FIG. 17, are simplified for convenience, but it will be appreciated that the above-mentioned time and labor are required.
In the illustrated conventional construction, the three wire harnesses 11 to 13 are connected together, and the serial data wires are spliced. In the case where four or more wire harnesses are connected together, there is required an operation in which sheaths are removed from end portions of serial data wires, and then terminals are connected to these ends. Then they are inserted into connectors. Therefore, in this case, there has been encountered a problem that the operation for splicing the serial data wires is more cumbersome.
In addition, the sheaths are removed from the ends of the serial data wires 11a, 12a, 12c and 13a, and the terminals are secured to these ends. Then these serial data wires are connected in a wire-to-wire manner by the connectors 14 and 15 and are spliced by the joint connector 19 for the wire harness 12. Thus, these operations are required, Therefore, the degree of freedom of the splicing position of the serial data wires is lowered, and the serial data wires need to be set to different lengths. In addition, the noise-shielding performance is lowered because of the increased amount of removal of the sheaths.
Further, in such a conventional splicing method, however, it is necessary to provide the wires 11a and 13a for connecting the wire harnesses 12a and 12c together, and to splice the wires A to C by connecting these wires 11a and 13a respectively to the joint connectors 14 and 15. Thus, there are required the two wires 11a and 13a provided over the wire harnesses 12a and 12c, and the number of the wires increases, and therefore, the production of the wire harnesses has become cumbersome.
In the conventional construction, the two wire harnesses 12a and 12c are connected together, thereby splicing the wires. In the case where three or more wire harnesses are connected together, a wire or wires, similar in construction to the wires 11a and 13a, are further needed, and the number of the wires further increases and therefore the production of the wire harnesses has become more cumbersome.
As shown in FIG. 13, in the case where splicing wires A, B and C of two wire harnesses (e.g., 12a and 12c in FIG. 17A) are connected together by a joint connector 6 (or 7), including bus bars 9a (see FIG. 15) having, for example, one input portion and three output portions, there are encountered problems that the joint connector 6 (or 7) has an increased size and that a large space is needed for mounting the large-size joint connector 6 (or 7) on a vehicle body panel.
It is therefore an object of this invention to provide a vehicle wiring construction or a wire harness structure in which the efficiency of an operation for splicing data communication wires, preferably in the form of serial data wires, can be enhanced, and the degree of freedom of the splicing position of the serial data wires can be enhanced, thereby enhancing the degree of freedom of setting of wire lengths. In addition, the amount of removal of sheaths from the serial data wires can be reduced, thereby enhancing the noise shielding performance.
To solve the above problems, the present invention provides a vehicle wiring construction that includes a plurality of sub wire harnesses each having an end connector. The sub wire harnesses are configured to be connected to each other when the end connectors are coupled to each other. Each sub wire harness has at least one joint wire attached thereto. At least one joint connector is provided, and is configured to hold and electrically interconnect the joint wires that are respectively attached to the sub wire harnesses. The at least one joint connector is configured to be positioned away from the end connectors so that the joint wires can be connected independently to the at least one joint connector without being connected to the end connectors.
In another aspect of the present invention, the at least one joint wire comprises at least one data communication wire. The data communication wires are configured to respectively extend between the at least one joint connector and electronic control units to transmit data to a respective one of the electronic control units. Accordingly, the electronic control units can be intercommunicated via the at least one joint connector. Preferably, the data communication wire is a serial data communication wire, and is formed from either one of a shielded wire, a twist pair wire or a tubed wire.
In a further aspect of the present invention, the data communication wires are of substantially the same length. Consequently, electrical characteristics of data communication between the electronic control units can be substantially the same.
In a further aspect of the present invention, the vehicle wiring construction has a sub-connector for receiving and holding the at least one joint wire attached to the sub wire harness. The sub-connectors are configured to be accommodated within the joint connector.
In a further aspect of the present invention, the at least one joint connector is mounted on an electrical connection box positioned in the proximity of the end connectors. Alternatively, the at least one joint connector may be mounted on a bracket of a vehicle body positioned in the proximity of the end connectors, or may be mounted at any suitable location such as the one at one of the sub wire harnesses, preferably in the proximity of the end connectors.
In another aspect of the present invention, the at least one joint connector is formed unitarily in one piece with an electrical connection box positioned in the proximity of said end connectors, and forms a joint wiring configuration to electrically interconnect the joint wires and an internal circuit of the electrical connection box.
Further, the present invention provides a wire harness structure in which a wire harness, including a serial data wire for effecting a serial data communication, is divided, and the divided wire harnesses are connected together through connection means, and a part of the serial data wire are spliced over the plurality of divided wire harnesses without being connected to the connection means. There is provided a sub-connector to which ends of the part of the serial data wire are connected. There is provided a joint connector for splicing the serial data wires disposed respectively within the sub-connector.
In this case, the serial data wires, provided on the wire harnesses, are connected to the sub-connector, and this sub-connector is connected to the joint connector. By doing so, the serial data wires, provided respectively on the plurality of wire harnesses, can be spliced over the wire harnesses.
As a result, a conventional operation, in which sheaths are removed from the end portions of the serial data wires, and then these end portions are connected to a connector, can be minimized. Therefore, the efficiency of the operation for splicing the serial data wires can be enhanced. Moreover, the end portions of the serial data wires do not need to be connected to the wire-to-wire connector which connects the wire harnesses together. Therefore, the splicing position of the serial data wires is prevented from being limited, and the degree of freedom of the splicing position of the serial data wires can be enhanced.
For installing the wire harnesses on the vehicle body, the serial data wires, provided respectively on the divided wire harnesses, are connected to the sub-connector, and the sub-connector is connected to the joint connector at the time of installing these wire harnesses on the vehicle body. By doing so, the serial data wires can be easily spliced. Therefore, the serial data wires can be easily connected to the proper portion of the joint connector in a collected manner.
In the invention, in order to solve the above problems, the serial data wire may be a shielded wire.
In the invention, in order to solve the above problems, the serial data wire may be a twist pair wire.
In the invention, in order to solve the above problems, the serial data wire may be a tubed wire.
Any one of the above serial data wires has noise-shielding properties, and therefore the noise-shielding performance can be positively enhanced.
In the invention, in order to solve the above problems, the serial data wires may be set to generally about the same length.
In this case, one end portions of the serial data wires are spliced at the joint connector while the other ends of these serial data wires are connected respectively to ECUs. The serial data wires may be set to generally about the same length. By doing so, high-speed communications can be effected in such a manner that impedance characteristics between the ECUs are kept constant through the serial data wires, and stable data communications can be effected in a stable, highly-precise manner.
In the invention, in order to solve the above problems, the joint connector may be provided in the vicinity of the connection means.
In this case the joint connector may be provided in the vicinity of the connection means through which the wire harnesses are connected together, and therefore, the connection between the wire harnesses and the splicing of the serial data wires can be effected at one time in a common space on the vehicle body at which only a narrow installation space is available because of the layout of the equipments and the like.
In the invention, in order to solve the above problems, the joint connector may be mounted on an electrical part fixedly mounted on the vehicle body.
In this case, if any electrical part, such as an ECU, a junction box, a relay box, a fuse box, a radio, a clock and various meters, can be provided in the vicinity of the connection means, and the joint connector may be mounted on this electrical part. By doing so, the region, at which electric power is supplied to the wire harnesses, and the region, at which the joint connector is fixedly mounted, can be set to the same region. Therefore, the space required for mounting the joint connector can be reduced.
In the invention, in order to solve the above problems, the joint connector may be mounted on a bracket mounted on the vehicle body.
In this case, when the bracket may be mounted on an arbitrary portion of the vehicle body, the position of mounting of the connection means is not limited, and the degree of freedom of the mounting position of the connection means can be increased.
In the invention, in order to solve the above problems, the joint connector may be mounted on an arbitrary one of the wire harnesses disposed in the vicinity of the connection means.
In this case, the joint connector can be fixed without the need for mounting any bracket on the vehicle body.
In the invention, in order to solve the above problems, the joint connector may contain a branch wiring for splicing a maximum of three serial data wires.
In this case, the joint connector can be formed into a compact, lightweight design, and therefore, the joint connector can be arranged easily by mounting the joint connector directly on the wire harness by a tape or on the nearby electrical part, so that the operations for installing and mounting the wire harnesses, including the serial data wires, can be effected easily.
The joint connector, serving as the splicing portion for the serial data wires, can be arranged freely, and therefore, the installation of the serial data wires can be simplified, thereby enhancing the efficiency of the mounting operation. In addition, each of the relatively-expensive serial data wires can be connected to the unit in the shortest path, thereby reducing the cost.
In the invention, in order to solve the above problems, the joint connector may be formed unitarily in one piece or integrally with an electronic unit, and contains a branch wiring for splicing two serial data wires and an internal circuit of the electronic unit.
In this case, the wire harness-connecting operation at the connector portion, the serial data wire-splicing operation, and the operation for connecting the electronic unit to ordinary wires can be effected at one time, and the efficiency of the operation for mounting the structure on the vehicle body can be further enhanced. In addition, the number of the serial data wires for respectively transferring serial data to the electronic units can be reduced, thereby further reducing the cost.
It is therefore an object of this invention to provide a wire harness structure in which the number of splicing wires may be prevented from increasing, thereby enabling the easy production of a wire harness, and besides the efficiency of an operation, in which the wire harness is mounted on a vehicle body, with the splicing wires easily collected, can be enhanced, and the cost of the wire harness structure is reduced.
Further more, the present invention provides a wire harness structure wherein a wire harness, including a plurality of wires, is divided, and the divided wire harnesses are connected together through connection means. The structure includes sub-connectors, which are separate from the connection means and to which ends of part of the wires of the divided wire harnesses are connected, and a joint connector, which is provided in the vicinity of the connection means so as to splice the wires disposed within the sub-connectors. The part of the wires of the wire harnesses are spliced together by the joint connector over the divided wire harnesses.
In this case, part of the wires of the divided wire harnesses may be connected to the sub-connectors, and these sub-connectors may be connected to the joint connector provided in the vicinity of the connection means. By doing so, part of the wires of the divided wire harnesses can be spliced over the wire harnesses.
As a result, splicing wires for connecting the wire harnesses together as in the conventional construction are not necessary, and the number of the wires is reduced. Thus, the production of the wire harness can be carried out easily.
For mounting the wire harnesses on a vehicle body, these wire harnesses can be supplied to a manufacturer in such a manner that parts of the wires, provided on the wire harnesses are connected to the sub-connectors, and therefore on the part of the manufacturer, the wires can be easily spliced together merely by connecting the sub-connectors to the joint connector. Therefore, the wires can be easily connected to the proper portion of the joint connector in a collected manner.
The joint connector may be provided in the vicinity of the connection means through which the divided wire harnesses are connected together, and therefore, the connection between the wire harnesses and the splicing of the wires can be effected in a common space on the vehicle body, at which only a narrow installation space is available because of the layout of electrical equipments, an engine and the like.
The joint connector for splicing purposes can be separate from the connection means. Therefore, the joint connector of high versatility can be formed into a compact and lightweight design, the cost is low, and the installation space for the joint connector can be reduced.
In the invention, in order to solve the above problems. the joint connector may be mounted on an electrical part fixedly mounted on a vehicle body.
In this case, if any electrical part, such as a fuse box, is provided in the vicinity of the connection means, the joint connector may be mounted on this electrical part. By doing so, the region, at which electric power is supplied to the wire harnesses, and the region, at which the joint connector is fixedly mounted, can be set to the same region, and the space required for mounting the joint connector can be reduced.
In the invention, in order to solve the above problems, the joint connector may be mounted on a bracket fixedly mounted on the vehicle body.
In this case, when the bracket is mounted on an arbitrary portion of the vehicle body, the position of mounting of the connection means is not limited, and the degree of freedom of the mounting position of the connection means can be increased.
In the invention, in order to solve the above problems, the joint connector may be mounted on the wire harness disposed in the vicinity of the connection means.
In this case, the joint connector can be fixed without the need for mounting any bracket on the vehicle body.